Table 4

Risk of adverse outcomes at birth by exposure group

OutcomeMetformin
(n=3967)		Combination treatment
(n=889)		Insulin (reference)
(n=5273)
Events*OR (95% CI)Events*OR (95% CI)†Events*
No.%UnadjustedIPTW weighted‡No.%UnadjustedIPTW weighted‡No.%
LGA1594.00.63
(0.52 to 0.76)		0.82
(0.67 to 0.99)		10411.72.00
(1.58 to 2.52)		1.58
(1.22 to 2.05)		3286.2
SGA922.31.93
(1.40 to 2.67)		1.65
(1.16 to 2.34)		151.71.40
(0.79 to 2.46)		1.21
(0.65 to 2.28)		641.2
Preterm birth2656.71.28
(1.07 to 1.52)		1.10
(0.91 to 1.31)		809.01.76
(1.36 to 2.28)		1.46
(1.10 to 1.95)		2805.3
Neonatal mortality50.12.22
(0.53 to 9.28)		1.30
(0.25 to 6.70)		30.35.95
(1.20 to 29.52)		1.31
(0.09 to 19.91)		30.1
Neonatal hypoglycemia69417.50.74
(0.67 to 0.82)		0.80
(0.72 to 0.89)		27230.61.54
(1.32 to 1.80)		1.29
(1.09 to 1.53)		117322.3
Neonatal hyperglycemia50.16.65
(0.78 to 56.97)		9.66
(0.72 to 130.37)		00.0NANA1<0.1
Any major congenital anomaly1514.50.90
(0.73 to 1.11)		0.79
(0.63 to 0.99)		355.11.03
(0.71 to 1.48)		0.75
(0.50 to 1.14)		2424.9

  • *The event numbers represent counts in the main cohort before trimming of children outside the overlapping range.

  • †Metformin and combination treatment were analyzed separately, in pairwise comparisons with insulin (reference in all analyses).

  • ‡Analyses were conducted in the main cohort after trimming of children outside the overlapping range of the propensity score. In the IPTW analyses of metformin versus insulin, 3671 children exposed to metformin and 5218 exposed to insulin included; in the analyses of combination treatment versus insulin, 882 children exposed to combination treatment and 5252 exposed to insulin included.

  • IPTW, inverse probability of treatment weighting; LGA, large for gestational age; NA, not applicable; SGA, small for gestational age.